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2006-08-28 20:11:15 · 11 answers · asked by PRI 1 in Science & Mathematics Weather

11 answers

The details of this are still rather poorly understood, as far as I can tell. The basic process goes something like the following. As you probably know, a cloud is just water vapor (steam, if you like), and is composed of very tiny water drops. Now, because the cloud is high in the sky, where the air is thin, these water drops get cold, below the freeaing point of water. But it turns out that absolutely pure water won't freeze by itself, even if you get below 32 degrees F, or 0 degrees C (though it will freeze on its own if you get it extremely cold). Instead, the water drops need to stick to something else, like a particle of dust, or smog, or even a bacterium. Only then does the water droplet freeze.

Once this has happened, other water droplets will stick to the newly made ice-crystal, and also freeze, making it larger. Depending on the conditions, different shaped crystals will grow. Generally, we see snowflakes having a six-sided symmetry. We can get a rough idea why this is by noting that in a water molecule (two hydrogen atoms and one oxygen atom stuck together), the angle between the two hydrogen atoms is about 120 degrees, which is also the angle between two sides of a regular hexagon (six-sided figure where all the sides are the same length). So in some rough sense, water molecules like to "fit together" in six-sided shapes, though this isn't always true.

The links below contain more information on snowflakes:

http://www.gi.alaska.edu/ScienceForum/ASF8/828.html
http://www.pa.msu.edu/~sciencet/ask_st/100897.html
http://tqjunior.advanced.org/3876/snowfacts.html
http://miavx1.acs.muohio.edu/~dragonfly/snow/icensnow.HTMLX

2006-08-28 20:18:09 · answer #1 · answered by hamdi_batriyshah 3 · 2 0

Huge amount of ice falling at one place will form the snow flakes

2006-09-02 00:40:47 · answer #2 · answered by badari n 1 · 0 0

The crystals form from Water Vapor in the clouds, called the sublimation process. The snowflakes get bigger when temperatures drop at 32°F (0°C) or below.

2006-08-30 01:08:39 · answer #3 · answered by Michael R 3 · 0 0

at the time of precipitation,if the temperature is below 0 degree,ten snow flakes are formed

2006-08-28 20:28:08 · answer #4 · answered by Rishav 2 · 0 0

rain water gets condensed further and falls on to the earth as snow flakes

2006-08-29 03:51:42 · answer #5 · answered by a b c 2 · 0 0

By water droplets freezing together in the upper areas of the atmosphere. After freezing together, they become heavy enough to fall to the earths' surface(actually, gravity causes the flakes to fall).

2006-09-02 14:32:29 · answer #6 · answered by Anonymous · 0 0

Crystallization of water under extreme cold (below freezing) temperature and pressure.

2006-08-28 20:19:14 · answer #7 · answered by ? 5 · 0 0

i hink they are formed in the sky and they come down how ever

2006-09-04 07:00:04 · answer #8 · answered by ~~~~**im to hot**~~~~ 1 · 0 0

frozen water vapor

2006-08-28 21:13:43 · answer #9 · answered by Anonymous · 0 0

cold

2006-08-28 23:55:04 · answer #10 · answered by bill j 4 · 0 0

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